The present invention relates to a fastener assembly device. More specifically, the present invention relates to a fastener assembly device for fastening workpieces together.
Fasteners of the type disclosed in U.S. Pat. No. 4,732,519 to Wagner were developed as a result of complaints from auto manufactures that fasteners for fastening a component to an engine would come out of the washer during transportation of the fastener assembly before use thereof. More specifically, as disclosed in U.S. Pat. No. 4,732,519, when the fastener is inserted through the washer, the annular ring or collar on the fastener becomes damaged in two places where the collar comes into contact with the inwardly protruding two nibs or protrusions of the washer. Consequently, when the fastener rotates, and the damage points line up with the protrusions on the washer, it becomes significantly easier for the fastener to become disassembled from the washer.
In the prior art fastener assemblies, the two protrusions are disposed 180 degrees apart. However, with the two protrusions spaced 180 degrees apart, the device is able to disassemble at two locations. The provision of three protrusions was found to require an increased force for assembly and disassembly. However, although such increased force is advantageous, the provision of three protrusions increases to three the number of locations in which the fastener and washer can become disassembled. In other words, when the protrusions and the damage points in the annular collar are aligned, the fastener can easily become disassembled. Such disassembly will also occur each time the fastener and washer are rotated relative to each other through one third of a revolution, that is, when each of the protrusions is disposed evenly spaced from an adjacent protrusion.
The aforementioned problem is overcome according to the present invention by the provision of protrusions that are unevenly spaced relative to each other. Applicants discovered that when the protrusions are unevenly spaced, the protrusions and damage points are aligned only one time when the fastener and washer are rotated relative to each other through one revolution. Such is the case when two, three or more protrusions are provided. Accordingly, the unevenly spaced protrusions of the present invention greatly reduce the chance of the damage points on annular collar lining up with the protrusions of the washer. More particularly, for an embodiment of the present invention having two protrusion, the protrusions will not be aligned 180 degrees relative to each other. Also, for an embodiment of the present invention having three protrusion, the protrusions will not be located 120 degrees relative to each other.
Therefore, it is a primary feature of the present invention to provide a fastener assembly device that overcomes the problems associated with the prior art arrangements.
Another feature of the present invention is the provision of a fastener assembly device that reduces the chances of the washer and fastener becoming disassembled prior to use
Other features and advantages of the present invention will be readily apparent to those skilled in the art by a consideration of the detailed description of a preferred embodiment of the present invention contained herein.
The present invention relates to a fastener assembly device for fastening workpieces together. The device includes an elongate fastener having a first and a second end. The fastener includes a head defined by the first end of the fastener and a threaded portion which extends between the second end of the fastener and the head. A shank portion is disposed between the head and the threaded portion and an annular collar is disposed between the head and the second end of the fastener. A washer cooperates with the fastener, the washer defining an aperture for the reception therethrough of the threaded portion of the fastener. The washer includes a plurality of protrusions which extend towards and cooperate with the annular collar. The arrangement is such that when the threaded portion of the fastener extends through the aperture of the washer, the protrusions interact with the collar for holding the fastener and the washer together. Also, each protrusion of the plurality of protrusions is unevenly spaced circumferentially from an adjacent protrusion.
In a more specific embodiment of the present invention, the head is a hexagonal type bolt head. Additionally, the head includes an integral spacer. The threaded portion extends from the second end of the fastener to the annular collar and shank portion extends from the head to the annular collar.
Furthermore, the annular collar is disposed between the shank portion and the threaded portion.
Moreover, the annular collar is integrally formed with and disposed between the shank portion and the threaded portion.
Additionally, the fastener including the annular collar are fabricated from steel.
Also, the washer includes a cylindrical portion having a first and a second extremity . A flange extends radially from the first extremity of the cylindrical portion. Also, a further radially extending flange extends from the second extremity of the cylindrical portion.
Moreover, the cylindrical portion defines the aperture for the reception therethrough of the threaded portion.
Additionally, the plurality of protrusions extend radially inwards from the cylindrical portion.
Also, the plurality of protrusions provide an interference fit with the annular collar when the threaded portion is moved axially through the aperture.
In one embodiment of the present invention, the plurality of protrusions includes only a first and a second protrusion. The arrangement is such that a first circumferential distance between the first and the second protrusions is less than a second circumferential distance between the first and the second protrusions. Also, the sum of the first and second distances is equal to a circumference of the annular collar.
In a further embodiment of the present invention, the plurality of protrusions includes a first protrusion and a second protrusion, the second protrusion being spaced a first circumferential distance from the first protrusion. Additionally, a third protrusion is provided, the third protrusion being spaced a second circumferential distance from the second protrusion. Also, the third protrusion is spaced a third circumferential distance from the first protrusion. Furthermore, the sum of the first, second and third distances is equal to a circumference of the annular collar.
Additionally, the first and second distances are unequal.
In another embodiment of the present invention, the second and third distances are unequal.
In yet another embodiment of the present invention, the first and third distances are unequal.
In a further embodiment of the present invention, the first, second and third distances are unequal.
Many modifications and variations of the present invention will be readily apparent to those skilled in the art by a consideration of the detailed description contained hereinafter taken in conjunction with the annexed drawings which show a preferred embodiment of the present invention. However, such modifications and variations fall within the spirit and of the present invention as defined by the appended claims.